The boys did not knock on the walls to send Morse messages to each other. Instead, Jem got into bed, as his uncle ordered, and Will dragged over his mattress and laid on Jem's floor, and they played games together on their phones. The sound of the games and the light from the little devices filled the room.

They called it a night only after Jem dropped his phone on his face because he was so tired and unable to hold it up any longer.

Will was still on Jem's bedroom floor when he woke up the next morning. But Jem was not there. Will got up and wandered out to the hallway where he found Elias sitting outside the closed toilet door. He heard Jem coughing inside.

"Morning, Will," Elias greeted. "Want the toilet? You'll have to wait your turn."

Will sat down next to Jem's uncle. A particularly loud bout of coughing and retching made Will cringe.

Elias noticed and said: "I swear, one day he's going to die in there." He shook his head disapprovingly. "I've told him a million times not to do his therapy without me. And not to lock the door. But he never listens."

"Is Jem really going to die?" Will asked.

"Eventually, yes," Elias confirmed. "Cystic fibrosis patients generally have a life expectancy of 30 to 40 years. But Jem's a bad case. The doctors think he won't live until 30, unless he gets a lung transplant."

Will struggled to process this information. A 30-year-old person seemed ancient to a 15-year-old boy. His sister Ella had been 17 when she died. "That doesn't seem too bad," Will remarked.

"It's bad," Elias assured him. "He'll likely never have kids, or, if he does, never see them grow up. He'll probably never hold down a proper job, because of all the health issues that'll take up his time. Fifteen years will fly by, and all too soon, they'll be gone."

Will rubbed his nose hard, feeling the prickling behind his eyes that signalled tears. He had learnt to recognise this sensation after Ella's death. While 30 years was an unimaginably long time for him, the concept of death wasn't. He could imagine a world without Jem and he didn't like it.

"Why did you run off last night?" Elias asked suddenly.

Will blinked, feeling wrong footed. "I had a row with my parents."

"Over?"

"Being forced to be tutored day and night. And being under house arrest. And… stuff," Will ended lamely.

"Stuff?"

"I don't want to talk about it," Will said fiercely.

"Look, sometimes parents do or say things that seem mean but they don't mean it to be mean. They're human too, you know?" Elias explained. "I only began to understand when Jem came to live with me. I'd try to do things that I thought helped him, but they really really didn't. He gets mad at me sometimes, believe it or not. But I try my best. I'm sure your parents do too.

"Sure, they may mess it up; no one gets it right all the time. Parenting is a whole series of trial and error, give and take. They're trying to do their best for you, but you have to work it out with them when they do it wrong. That's why you should go home today and talk to your parents. Whatever 'stuff' is, it can be fixed."

Will shook his head. "It's unfixable."

"Nothing's unfixable. Whatever you did, your parents won't stay mad at you forever. Parents are good that way. Like, I could be mad at Jem for a while – I think we once went a week without speaking to each other – but I still love him. I'm sure it's the same with your parents. Whatever happened, it'll blow over, but someone has to make the first step to fix it. Best if it's you. Gesture of good will, you know?"

Will didn't really believe him, but just mumbled "yeah". All the grown-up talk was making him uncomfortable and he didn't want to deal with such complex matters in the morning. He stood up to go away.

"By the way, you can use the kitchen sink if you just want to brush your teeth. I don't know how long Jem is going to take in there," Elias suggested.

Will had slept in a tshirt Elias had lent him, as Jem's clothes were too small for him. He returned to the spare room and changed back into his own clothes. He then went down to the kitchen and found Colette stirring something in the pot. At the side, there were four plates with portions of crumpets and eggs distributed.

"What're you cooking?" Will asked, leaning over the pot. There was something that looked like mashed potatoes but green in colour.

"You've never tried this before?" Colette asked. She had a slight accent to her voice and Will liked to hear her speak.

"No."

"Then I'm not going to tell you till you try it," she said.

Will grimaced. "I don't it when people say that. It's pretty guaranteed I'll hate it. It's mushy peas, isn't it? I hate mushy peas."

Colette laughed. "It's not mushy peas."

"Then what is it? Does Jem like it?" Will continued to ask.

"Jem doesn't like a lot of food. I wouldn't trust his likes and dislikes," Colette advised. "He doesn't even like fried chicken. Do you know of any other teenage boy who doesn't like fried chicken? Or pizza? Or, you know, junk food?"

"Are you guys making fun of me?" Jem asked, walking into the kitchen. He was still dressed in grey Shaun the Sheep pyjamas. He went over and perched on a tall stool over by the counters. He still looked half asleep.

"Good morning, sleepyhead," Colette greeted. "Why aren't you dressed yet? Where's your uncle?"

"Toilet."

"That jerk! I told him to tell me when you were done. I was supposed to be next in line for the toilet!" Colette gave the green stuff in the pot and extra hard stir in annoyance. "We're not going to wait for him for breakfast, boys," she said conspiratorially. "Jem, could you put the kettle on for the tea?"

Jem complied, yawning as he stood by the sink to fill the kettle. Will was given the task of spooning out portions of the green stuff onto the plates.

Breakfast was hot buttered crumpets with poached eggs and the green stuff. Colette sprinkled salt, pepper and olive oil on it. She also poured out glasses of milk for the two boys to have in addition to their tea. Will hungrily dug in. He found the green stuff to have quite an interesting flavour – creamy, nutty and buttery.

"Can you tell me what this stuff is now, Colette?" Will asked.

"It's mashed avocado," she told him. "Do you like it?"

"It's… ok," Will replied. His appetite for it disappeared after being told what it was.

"What are you boys doing today?" Colette asked conversationally.

Jem looked up from his breakfast. "I thought Will was supposed to call home. That's what Uncle said," he said.

"I don't have to, though," Will countered.

Elias walked in then. "What are you guys talking about?"

"What the boys are going to do today," Colette said.

"Will's going home to thrash things out with his parents, isn't he?" Elias asked, as though that had always been the plan. Will squirmed in his chair; he had hoped Elias had forgotten. Jem's uncle noticed his discomfort. "Come on, Will, we've talked about this. Your parents would have had time to cool down by now so it's a good time to talk. There's nothing that can't be solved just as long as everyone sits down and has a proper talk."

"Yes there is. They're going to kill me. I don't wanna go back," Will pleaded. "Jem, don't make me."

"I'm sorry, Will, but I agree with Uncle on this one," Jem said apologetically. "You know yourself that Cecily has been frantically texting me all night asking if you were here."

"Your family has been looking for you? Did you answer them, Jem?" Elias asked.

"No. Will told me not to," Jem said.

Colette put down her fork and said sternly, "Jem, you shouldn't have just ignored the texts! What if it had been an emergency?"

"But Will didn't want me to, "Jem repeated, looking bewildered.

Elias firmly put his foot down. "I thought you had better sense than that, Jem. We're finishing breakfast, then I'm taking Will back home. End of discussion."

"Don't throw him to the sharks, Uncle!" Jem exclaimed.

"They are his parents, not sharks," Elias said exasperatedly. "Eat your breakfast. We'll all take Will home; do you prefer that? Bit of buffer and support?"

"I guess," Jem grudgingly accepted. He looked over at Will, who was going pale. "Will?"

"Do I have a choice?" Will asked.

"No, you don't," Elias said firmly.

Breakfast was a slow affair. Jem was usually a very slow eater, but today, Will dragged things out as much as he could, with the result that he finished eating even after Jem did. By the time he was done, Jem had already changed and was waiting for him in the living room.

Will took his time to wash his plate and dry it, and then moved at a snail's pace to put on his shoes. Elias and Colette were looking askance at him, but said nothing.

Jem handed him a coat to put on – he guessed that it was supposed to be Jem's for it had a print of music notes on it. It fit him just fine. There was a taxi parked outside the house. Elias now hurried them a little, not wanting to keep the taxi waiting.

The drive to Belgravia was shorter than Will liked, and it seemed like no time at all before they pulled up outside the Herondale townhouse. The four-storey house seemed to loom judgementally over him as he walked up the steps to the front door. He glared at the hulking edifice. Once he reached the front door, he hesitated. There was still time for him to run off – he knew this neighbourhood better than any of them. He could still get away.

But before he could decide on any getaway plan, Elias stepped up next to him and rang the doorbell. The door opened after a few moments.

"So, you decided to come back," Mr Herondale observed.

Will froze in fright when he saw his father. Suddenly, running away seemed a much more enticing prospect.